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[XFS] Reduce xfs_bmapi stack use by removing some local state variables,

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and directly testing flags instead.

SGI-PV: 947312
SGI-Modid: xfs-linux-melb:xfs-kern:25370a

Signed-off-by: Nathan Scott <nathans@sgi.com>
This commit is contained in:
Nathan Scott 2006-03-14 13:33:50 +11:00
parent 220b528413
commit 39269e29d4
1 changed files with 37 additions and 42 deletions
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79
fs/xfs/xfs_bmap.c
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@ -4629,10 +4629,6 @@ xfs_bmapi(
xfs_btree_cur_t *cur; /* bmap btree cursor */
xfs_fileoff_t end; /* end of mapped file region */
int eof; /* we've hit the end of extents */
char contig; /* allocation must be one extent */
char delay; /* this request is for delayed alloc */
char exact; /* don't do all of wasdelayed extent */
char convert; /* unwritten extent I/O completion */
xfs_bmbt_rec_t *ep; /* extent record pointer */
int error; /* error return */
xfs_bmbt_irec_t got; /* current file extent record */
@ -4651,13 +4647,9 @@ xfs_bmapi(
int tmp_logflags; /* temp flags holder */
int whichfork; /* data or attr fork */
char inhole; /* current location is hole in file */
char stateless; /* ignore state flag set */
char trim; /* output trimmed to match range */
char userdata; /* allocating non-metadata */
char wasdelay; /* old extent was delayed */
char wr; /* this is a write request */
char rt; /* this is a realtime file */
char rsvd; /* OK to allocate reserved blocks */
#ifdef DEBUG
xfs_fileoff_t orig_bno; /* original block number value */
int orig_flags; /* original flags arg value */
@ -4694,15 +4686,8 @@ xfs_bmapi(
XFS_STATS_INC(xs_blk_mapw);
else
XFS_STATS_INC(xs_blk_mapr);
delay = (flags & XFS_BMAPI_DELAY) != 0;
trim = (flags & XFS_BMAPI_ENTIRE) == 0;
userdata = (flags & XFS_BMAPI_METADATA) == 0;
convert = (flags & XFS_BMAPI_CONVERT) != 0;
exact = (flags & XFS_BMAPI_EXACT) != 0;
rsvd = (flags & XFS_BMAPI_RSVBLOCKS) != 0;
contig = (flags & XFS_BMAPI_CONTIG) != 0;
/*
* stateless is used to combine extents which
* IGSTATE flag is used to combine extents which
* differ only due to the state of the extents.
* This technique is used from xfs_getbmap()
* when the caller does not wish to see the
@ -4718,10 +4703,9 @@ xfs_bmapi(
* xfs_strat_comp(), where the xfs_bmapi() call
* is transactioned, and the extents combined.
*/
stateless = (flags & XFS_BMAPI_IGSTATE) != 0;
if (stateless && wr) /* if writing unwritten space, no */
wr = 0; /* allocations are allowed */
ASSERT(wr || !delay);
if ((flags & XFS_BMAPI_IGSTATE) && wr) /* if writing unwritten space */
wr = 0; /* no allocations are allowed */
ASSERT(wr || !(flags & XFS_BMAPI_DELAY));
logflags = 0;
nallocs = 0;
cur = NULL;
@ -4756,7 +4740,7 @@ xfs_bmapi(
if (eof && !wr)
got.br_startoff = end;
inhole = eof || got.br_startoff > bno;
wasdelay = wr && !inhole && !delay &&
wasdelay = wr && !inhole && !(flags & XFS_BMAPI_DELAY) &&
ISNULLSTARTBLOCK(got.br_startblock);
/*
* First, deal with the hole before the allocated space
@ -4768,7 +4752,7 @@ xfs_bmapi(
* allocate the stuff asked for in this bmap call
* but that wouldn't be as good.
*/
if (wasdelay && !exact) {
if (wasdelay && !(flags & XFS_BMAPI_EXACT)) {
alen = (xfs_extlen_t)got.br_blockcount;
aoff = got.br_startoff;
if (lastx != NULLEXTNUM && lastx) {
@ -4790,8 +4774,8 @@ xfs_bmapi(
got.br_startoff - bno);
aoff = bno;
}
minlen = contig ? alen : 1;
if (delay) {
minlen = (flags & XFS_BMAPI_CONTIG) ? alen : 1;
if (flags & XFS_BMAPI_DELAY) {
xfs_extlen_t extsz;
/* Figure out the extent size, adjust alen */
@ -4804,7 +4788,9 @@ xfs_bmapi(
if (extsz) {
error = xfs_bmap_extsize_align(mp,
&got, &prev, extsz,
rt, eof, delay, convert,
rt, eof,
flags&XFS_BMAPI_DELAY,
flags&XFS_BMAPI_CONVERT,
&aoff, &alen);
ASSERT(!error);
}
@ -4842,24 +4828,29 @@ xfs_bmapi(
if (rt) {
error = xfs_mod_incore_sb(mp,
XFS_SBS_FREXTENTS,
-(extsz), rsvd);
-(extsz), (flags &
XFS_BMAPI_RSVBLOCKS));
} else {
error = xfs_mod_incore_sb(mp,
XFS_SBS_FDBLOCKS,
-(alen), rsvd);
-(alen), (flags &
XFS_BMAPI_RSVBLOCKS));
}
if (!error) {
error = xfs_mod_incore_sb(mp,
XFS_SBS_FDBLOCKS,
-(indlen), rsvd);
-(indlen), (flags &
XFS_BMAPI_RSVBLOCKS));
if (error && rt)
xfs_mod_incore_sb(mp,
XFS_SBS_FREXTENTS,
extsz, rsvd);
extsz, (flags &
XFS_BMAPI_RSVBLOCKS));
else if (error)
xfs_mod_incore_sb(mp,
XFS_SBS_FDBLOCKS,
alen, rsvd);
alen, (flags &
XFS_BMAPI_RSVBLOCKS));
}
if (error) {
@ -4892,7 +4883,7 @@ xfs_bmapi(
/* Indicate if this is the first user data
* in the file, or just any user data.
*/
if (userdata) {
if (!(flags & XFS_BMAPI_METADATA)) {
bma.userdata = (aoff == 0) ?
XFS_ALLOC_INITIAL_USER_DATA :
XFS_ALLOC_USERDATA;
@ -4904,7 +4895,7 @@ xfs_bmapi(
bma.firstblock = *firstblock;
bma.alen = alen;
bma.off = aoff;
bma.conv = convert;
bma.conv = (flags & XFS_BMAPI_CONVERT);
bma.wasdel = wasdelay;
bma.minlen = minlen;
bma.low = flist->xbf_low;
@ -4915,7 +4906,8 @@ xfs_bmapi(
* is larger than a stripe unit.
*/
if (mp->m_dalign && alen >= mp->m_dalign &&
userdata && whichfork == XFS_DATA_FORK) {
(!(flags & XFS_BMAPI_METADATA)) &&
(whichfork == XFS_DATA_FORK)) {
if ((error = xfs_bmap_isaeof(ip, aoff,
whichfork, &bma.aeof)))
goto error0;
@ -4978,7 +4970,7 @@ xfs_bmapi(
}
error = xfs_bmap_add_extent(ip, lastx, &cur, &got,
firstblock, flist, &tmp_logflags, whichfork,
rsvd);
(flags & XFS_BMAPI_RSVBLOCKS));
logflags |= tmp_logflags;
if (error)
goto error0;
@ -4990,7 +4982,7 @@ xfs_bmapi(
ASSERT(got.br_startoff + got.br_blockcount >=
aoff + alen);
#ifdef DEBUG
if (delay) {
if (flags & XFS_BMAPI_DELAY) {
ASSERT(ISNULLSTARTBLOCK(got.br_startblock));
ASSERT(STARTBLOCKVAL(got.br_startblock) > 0);
}
@ -5019,14 +5011,15 @@ xfs_bmapi(
* Then deal with the allocated space we found.
*/
ASSERT(ep != NULL);
if (trim && (got.br_startoff + got.br_blockcount > obno)) {
if (!(flags & XFS_BMAPI_ENTIRE) &&
(got.br_startoff + got.br_blockcount > obno)) {
if (obno > bno)
bno = obno;
ASSERT((bno >= obno) || (n == 0));
ASSERT(bno < end);
mval->br_startoff = bno;
if (ISNULLSTARTBLOCK(got.br_startblock)) {
ASSERT(!wr || delay);
ASSERT(!wr || (flags & XFS_BMAPI_DELAY));
mval->br_startblock = DELAYSTARTBLOCK;
} else
mval->br_startblock =
@ -5048,7 +5041,7 @@ xfs_bmapi(
} else {
*mval = got;
if (ISNULLSTARTBLOCK(mval->br_startblock)) {
ASSERT(!wr || delay);
ASSERT(!wr || (flags & XFS_BMAPI_DELAY));
mval->br_startblock = DELAYSTARTBLOCK;
}
}
@ -5074,7 +5067,7 @@ xfs_bmapi(
mval->br_state = XFS_EXT_NORM;
error = xfs_bmap_add_extent(ip, lastx, &cur, mval,
firstblock, flist, &tmp_logflags, whichfork,
rsvd);
(flags & XFS_BMAPI_RSVBLOCKS));
logflags |= tmp_logflags;
if (error)
goto error0;
@ -5091,9 +5084,10 @@ xfs_bmapi(
continue;
}
ASSERT(!trim ||
ASSERT((flags & XFS_BMAPI_ENTIRE) ||
((mval->br_startoff + mval->br_blockcount) <= end));
ASSERT(!trim || (mval->br_blockcount <= len) ||
ASSERT((flags & XFS_BMAPI_ENTIRE) ||
(mval->br_blockcount <= len) ||
(mval->br_startoff < obno));
bno = mval->br_startoff + mval->br_blockcount;
len = end - bno;
@ -5108,7 +5102,8 @@ xfs_bmapi(
mval[-1].br_startblock != HOLESTARTBLOCK &&
mval->br_startblock ==
mval[-1].br_startblock + mval[-1].br_blockcount &&
(stateless || mval[-1].br_state == mval->br_state)) {
((flags & XFS_BMAPI_IGSTATE) ||
mval[-1].br_state == mval->br_state)) {
ASSERT(mval->br_startoff ==
mval[-1].br_startoff + mval[-1].br_blockcount);
mval[-1].br_blockcount += mval->br_blockcount;